Mainworld Data

(III) Tolchan

(III) Tolchan is designated the mainworld. It orbits the primary at a mean distance of 0.81 AU (121.2 million km), within the habitable zone. It has an orbital period of 302 days 16 hours and a rotation period of 19.5 hours. The axial tilt is 22 degrees. Tolchan has a diameter of 6,516 km, a density of 5.18 g/cm³, and a surface gravity of 0.48 G. The world is geologically active. Its atmosphere is rated as Thin, Tainted, with a mean surface pressure of 0.49 bar and a composition of 85% nitrogen (N2), 14% oxygen (O2), and 1% argon (Ar), water vapor (H2O), carbon dioxide (CO2), neon (Ne) and other trace gases. The taint is caused by the low percentage of atmospheric oxygen. Approximately 31% of the surface is covered in seas of liquid water: average tidal ranges exceed 0.4m. Mean surface temperature: 3°C. The atmosphere is slow and moderate weather systems driven by the star and the seas work across the globe. The climate is seasonal.

Mainworld geography and topography

Total surface area: 133 million km², Land surface area: 92 million km², Water surface area: 41 million km².

Native Lifeforms

Tolchan, the mainworld, lying within the habitable zone, has extensive native life, consisting of minute multicellular organisms that can be found in most ecological niches. Their metabolic functions drive the process of atmospheric renewal.

The cold marginally hospitable world lying in orbital position (IV) (within the H+ region of the outer system) has primitive native life, consisting entirely of microscopic cyanobacteria-parallels that exist in any location where they can find even a minimal trace of water and warmth. Their metabolic functions maintain the process of atmospheric renewal.